Many ML models use neural networks, which are roughly modeled after neurons in the human brain and can detect patterns from data inputs. As a result, over time, a variety of NN (neural networks) topologies have been developed, each based on a particular sort of neural network layer.

With today’s huge choice of machine learning frameworks and tools, almost anybody with a basic understanding of machine learning may readily design a model with many sorts of neural network topologies. The majority of the time, it’s all about figuring out which issues each sort of neural network excels at and maximizing their hyperparameter setups.

  • Convolution, Deconvolution, Fully connected, and Recurrent are the four most frequent forms of neural network layers.

Convolution Layer type

In a CNN, a Convolution Layer is an essential sort of layer. Its most typical application is for finding features in pictures, where it employs a filter to scan an image a few pixels at a time and returns a feature map that categorizes each feature discovered.

The filter (kernel) is a set of n-dimensional weights multiplied by the input, with the filter’s dimensions matching the input’s. The filter expresses the likelihood that a particular pixel pattern indicates a feature.

As a result, the number of filter weights is less than the input, and the layer’s convolution process performs multiplication on “patches” of the picture that fit the filter size.

To find characteristics, multiplication is done systematically from left to right and top to bottom throughout the whole image. The stride is the number of pixels by which the filter travels for the next iteration. Padding around the input picture can be used to ensure that the filter always fits within the image’s entire boundaries for a particular stride.

Deconvolution Layer type

A Deconvolution Layer is an inverted process that efficiently up-samples data. Pictures or feature maps created from a convolution, as well as other forms of data, can be included. The upsampling resolution provided by deconvolution for picture data may be the same as or different from the original input image.

Fully connected Layer type

Every neuron in one layer communicates with every neuron in the next. All varieties of neural networks, from ordinary neural networks to convolutional neural networks, have fully linked layers (CNN).

As the size of the input expands, fully linked layers can become computationally costly, resulting in a combinatorial explosion of vector operations to execute and potentially poor scalability. As a result, they’re frequently utilized in neural networks for specialized tasks like picture data classification.

Recurrent Layer type

A Recurrent Layer has a “curving” capacity, which means it may take both the data to analyze and the output of a prior calculation conducted by that layer as input.

  • Recurrent neural networks (RNNs) are built on recurrent layers, which effectively provide memory – the ability to preserve a state across repetitions.

Their recursive structure makes RNNs ideal for applications requiring sequential input such as natural language and time series. They’re also handy for translating multiple types and dimensions of inputs to outputs.


When it concerns deep learning, neural networks are the true state, and there are several topologies and layer types to pick from. Each form of neural network specializes in addressing a certain set of problems, and hyperparameters are used to fine-tune those answers. Furthermore, ML practitioners now have access to a plethora of frameworks and tools that enable implementing ML models based on neural network topologies easier than ever.